1. Field of the Invention
This invention relates generally to an apparatus for interlocking adjacent circuit breakers having dissimilar actuating means so as to prevent the circuit breakers from simultaneously being in a closed operating position.
2. Background Information
There are a number of applications where it is required that the operation of two circuit breakers be coordinated such that only one circuit breaker can be in the closed or "on" operating position at a time. One such application is providing a load with electrical power from either of two different sources, such as for example, a commercial power system and an auxiliary supply. It is imperative in such applications that only one circuit breaker be in the closed operating position at a time to preclude interconnecting the two different sources. For this particular application, as well as other applications, it is known to provide an interlock to prevent the circuit breakers from simultaneously being in the closed operating position.
One such interlock, disclosed in U.S. Pat. No. 4,286,242, is designed specifically for use with circuit breakers and utilizes plungers which engage the internal operating mechanisms of the circuit breakers. This interlock provides for the circuit breakers to be aligned end-to-end and to be similar type circuit breakers with the same type of actuating means for actuating the internal operating mechanisms.
Other interlocks are known which couple the actuating means, e.g., operating handles, of the circuit breakers whose operation is to be coordinated.
Typically the circuit breakers and the type of actuating means employed by the circuit breakers are similar, if not identical, allowing for a somewhat symmetrical interlock device to be employed. However, we are not aware of any such interlock which is capable of interlocking circuit breakers having dissimilar actuating means.
There is a need, therefore, for an interlock overcoming the above described limitations and disadvantages of the prior art.
There is also a need for an interlock which prevents adjacently positioned circuit breakers having dissimilar actuating means from simultaneously being in a closed or "on" operating position.
There is a need for an interlock which may be utilized with existing circuit breaker designs with minimal or no modifications to the existing circuit breakers.
There is a further need for an interlock which provides a visual indication of which circuit breaker is in the closed or "on" operating position and which breaker is locked-off, i.e., in the open or "off" operating position.